// Copyright 2019 CUE Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package protobuf

import (
	"text/scanner"

	"github.com/emicklei/proto"
)

func protoToCUE(typ string, options []*proto.Option) (ref string, ok bool) {
	t, ok := scalars[typ]
	return t, ok
}

var scalars = map[string]string{
	// Differing
	"sint32":   "int32",
	"sint64":   "int64",
	"fixed32":  "uint32",
	"fixed64":  "uint64",
	"sfixed32": "int32",
	"sfixed64": "int64",

	// Identical to CUE
	"int32":  "int32",
	"int64":  "int64",
	"uint32": "uint32",
	"uint64": "uint64",

	"double": "float64",
	"float":  "float32",

	"bool":   "bool",
	"string": "string",
	"bytes":  "bytes",
}

var timePkg = &protoConverter{
	goPkg:     "time",
	goPkgPath: "time",
}

func (p *protoConverter) setBuiltin(from, to string, pkg *protoConverter) {
	p.scope[0][from] = mapping{to, pkg}
}

func (p *protoConverter) mustBuiltinPackage(pos scanner.Position, file string) {
	// Map some builtin types to their JSON/CUE mappings.
	switch file {
	case "gogoproto/gogo.proto":

	case "google/protobuf/duration.proto":
		p.setBuiltin("google.protobuf.Duration", "time.Duration", timePkg)

	case "google/protobuf/timestamp.proto":
		p.setBuiltin("google.protobuf.Timestamp", "time.Time", timePkg)

	case "google/protobuf/any.proto":
		p.setBuiltin("google.protobuf.Any", "_", nil)

	case "google/protobuf/empty.proto":
		p.setBuiltin("google.protobuf.Empty", "{}", nil)

	default:
		failf(pos, "import %q not found", file)
	}
}